1. Technical Field.
The present invention relates generally to electrical lighting sources. More particularly, it relates to emergency electrical lighting sources.
2. Description of the Prior Art.
Under current local fire and building codes, buildings to which the public has access are required to have emergency lighting devices. These devices must provide specific amounts of illumination and have emergency backup power sources to provide emergency illumination to lights for a specified period of time during periods when utility power to the building is discontinued, thereby facilitating egress of persons from the building.
Traditionally, two incandescent lamps driven by a self-contained emergency battery power supply are used for illumination during power failure situations. A switching or transfer device will automatically operate the emergency illumination system when a power failure is detected.
While these traditional lighting arrangements perform adequately, they do have a few drawbacks. A major drawback is that the incandescent bulbs use large amounts of electrical power, thus requiring a relatively large emergency battery power supply for use during emergency lighting situations. Furthermore, while the incandescent bulbs provide adequate illumination, such bulbs do not have a long life in service and require frequent replacement.
It is an object of the present invention to provide a novel emergency lighting device using commercially available halogen lamps.
It is also an object to provide such a lighting device which allows the halogen lamps to be powered by an emergency battery power supply and associated charging and transfer circuitry during emergency power situations.
Still another object is to provide such a lighting device in which the halogen lamps are arranged to provide the amount of illumination required by building codes.
A further object is to provide such a lighting device which may be readily and economically fabricated and will enjoy a long life in operation.